コード例 #1
0
        public MuComFrame(byte[] inputBuffer)
        {
            if (inputBuffer is null)
            {
                throw new ArgumentNullException(nameof(inputBuffer));
            }
            if (inputBuffer.Length < 2)
            {
                throw new ArgumentException("Input buffer must contain at least two elements");
            }

            //Copy buffer
            this.RawBuffer = new byte[inputBuffer.Length];
            inputBuffer.CopyTo(this.RawBuffer, 0);

            //Decode header
            this.Description = MuComFrame.GetFrameDescriptionFromHeader(this.RawBuffer[0]);
            this.ID          = MuComFrame.GetIdFromFrame(this.RawBuffer);
            this.DataCount   = MuComFrame.GetDataByteCountFromHeader(this.RawBuffer[0]);

            //A read request frame is only two bytes long and does not
            if (this.Description == MuComFrameDesc.ReadRequest)
            {
                this.DataBytes = new byte[0];
                return;
            }

            //Check input frame size
            int expectedLength = MuComFrame.GetFrameSizeFromDataCount(this.Description, this.DataCount);

            if (inputBuffer.Length < expectedLength)
            {
                throw new ArgumentException("Input buffer size too small! " + expectedLength.ToString() + " expected but input buffer contains only " + inputBuffer.Length.ToString() + " bytes.");
            }

            //Create buffer for data bytes and intermediate buffer
            byte[] buffer = new byte[this.DataCount + 1];
            this.DataBytes = new byte[this.DataCount];

            //Reconstruct data from frame
            //Buffer[0..8] = Data bytes (first byte will be index)
            int dataPos = 0;
            int bytePos = 1;

            for (int i = 0; i < (this.DataBytes.Length + 1); i++)
            {
                if (bytePos < 0)
                {
                    bytePos = 6;
                    dataPos++;
                }
                buffer[i] = (byte)(this.RawBuffer[dataPos] << (7 - bytePos));
                dataPos++;
                buffer[i] |= (byte)(this.RawBuffer[dataPos] >> bytePos);
                bytePos--;
            }

            //Copy data
            this.ID = buffer[0];
            Array.Copy(buffer, 1, this.DataBytes, 0, this.DataBytes.Length);
        }